Verified PostgreSQL versions -- didn't actually run the program, but just checked the documentation

Last update (YYYY-MM-DD) -- 2018-3-17

Description -- Active Record connects classes to relational database tables to establish an almost zero-configuration persistence layer for applications. The library provides a base class that, when subclassed, sets up a mapping between the new class and an existing table in the database. In the context of an application, these classes are commonly referred to as models. Models can also be connected to other models; this is done by defining associations.